The problem you encountered is evident by this part of the VAM0093J msg: VAM0093J REDUCE OPERATION HALTED BECAUSE MINIMUM_PERCENT VALUE REACHED, OR CANNOT REDUCE BELOW 1 AVR UNIT
Looking for the instances of SET &RB = n and SET &MP = n, there are multiple instances where the value of &RB and/or &MP was less than 10. Setting &RB to a value less than 10 can cause additional overhead. Setting &MP to a value less than 10 can cause the VAM0093J errors because VAM is not able to reduce the allocation or extent amount to that small of a value.
It would be suggested that all of the &RB and &MP statements do not specify a value less than 10.